Method and blank for making axle housings



Aug. 14, 1934. F. HABICHT METHOD AND BLANK FOR MAKING AXLE HOUSINGS Filed Oct. 24, 1930 Patented Aug. 14, 1934 UNITED STATES METHOD AND BLANK FOR MAKING AXLE HOU SINGS Frank Habicht, Buchanan, Mich., assignor to Clark Equipment Company, Buchanan, a corporation of Michigan Mich.,

Application October 24, 1930, Serial No. 490,829

11 Claims.

This invention relates to axle housings.

In the copending application of George Spatta, Serial No. 416,537, filed December 26, 1929, .is'disclosed a method of forming a banjo type rear axle' housing from a piece of steel tubing by a plurality of forging and forming operations. The housing resulting from an application of this method is a banjo type housing having integrally formed flanges at its opposite ends to which the brake members of the vehicle are attached.

In the practice of that method, the cost of the finished housing is controlled by the cost of steel tubing of suitable character to permit it to be employed as blanks in the process. In view of the relatively extensive working of the metal of the'steel tubing in the fabrication of axle housings as there practiced, a seamless tube has been employed heretofore because such welded steel tubing as is now available on the market is not satisfactory, as the welds are not uniform. That is, some of the welds will not withstand the stresses imposed upon them and they rupture during the fabrication of the housing. This results in excessive rejects and runs up costs.

The present invention is an improvement on the invention covered in said prior copending application.

In the preferred embodiment of my invention,

the axle housing is made from a rectangular blank of substantially flat hot rolled sheet stock of suitable thickness, which blank is sheared from the sheet. This blank is of a width slightly less than the circumferential length at the critical section where the banjo frame and throat join. The thickness is preferably such as to permit stretching at this critical section to make up the said circumferential length. The width of the blank is, therefore, less than that required where a mere folding or shaping operation of the prior art is performed. Preferably, but not necessarily, the blank is of hot rolled stock, as it comes from the rolls. It need not be pickled or oiled. The lengthof the fiat blank is less than the length of the metal after the operation of swaging down the arms. The blank is perforated with a pair of slots either before or after it is formed into a cylinder or tube. The tubular blank is of uniform diameter throughout its 5 length.

The tubular blank thus formed is shrunk by endwise swaging in a pair of ring dies to form smaller diameter end cylinders or arms which are coupled to the larger diameter central cylinder by frusto conical sections, this shrinking preferably being accomplished in the manner set forth in the first above mentioned copending application.

After the blank has thus been formedto the required shape and length and before the banjo slot is opened out, the longitudinal seam formed by the abutting edges of the fiat stock from which it was made is welded by a weld running longitudinally of the blank. Preferably, the 'slots punched in the fiat stock are located so that this seam comes midway between the two slots in the finished blank, although, obviously, by suitable location of the slots the seam can be made to fall at any point on the circumference of the cylinder.

The steps of working the metal of the tubular blank follow closely the steps of the said prior application Serial No. 416,537, to which reference may be made for a further detailed ex planation of such steps. However, it is to be noted that the slots may be punched while the stock is fiat or after it is formed into the tubular blank. If the latter, the punching operation and dies may be the same as disclosed in the copending application of George Spatta, Serial No. 417,581, filed December 30, 1929, to which reference is made.

The shrinking of the arms occurs while the tubular blank is not yet welded. The edges of the metal abut and, as the swaging of the blank is by ring dies passed endwise over the arms, compression stresses only occur. The means for performing this operation are shown in the coa pending application of George Spatta, Serial No. 418,827, filed January 6, 1930, to which ref-' erence is made.

After the shrinking operation, the longitudinal seam is'welded by a suitable process of fusion welding which leaves the fused metal in substantially the same physical and chemical condition -as before fusing. Then the central part is heated, the slots are opened out, and the banjo frame formed according to the method and means disclosedin the applications of George Spatta, Serial No. 420,596, filed June 13, 1930, Serial No. 425,426, filed February 3, 1930, and Serial No. 426,545, filed February "I, 1930, to which reference is made.

The throat is then formed according to the method and means disclosed inthe copending application of George Spatta, Serial No. 427,204, filed February 10, 1930, towhich reference is made.

The flange of the banjo frame is bored and flattened as disclosed in the application of George Spatta, Serial No. 428,653, filed February 15, 1930, to which reference is now made.

The ends of the arms are then upset and flanged according to the method and means disclosed in the copending application of George Spatta, Serial No. 430,206, filed February 21, 1930, to which reference is made.

The banjo frame and fianges are reenforced by a backing strip welded into place in sections on each side, and the banjo frame and flanges are machined. The spring clips are then attached in place according to the welding method shown in the application of George Spatta, Serial No. 428,654, filed February 15, 1930, to which reference is made, or according to the construction and method shown in the application of Mogford and Spatta, Serial No. 482,401, filed September 17, 1930, to which reference is here made.

Now to acquaint those skilled in the art with the teachings of my invention, reference is made to the accompanying drawing in which a preferred embodiment of it is shown by way of example, and in which:

Figure 1 is a plan view of the blank at the end of the first step in my improved process;

Figure 2 is an end view of the blank shown in Figure 1;

Figure 3 is a plan view of the stock at the completion of the preferred first forming step;

Figure 4 is an end view of the blank shown in Figure 3;

Figure 5 is an elevational view of the blank at the completion of the preliminary forming operations;

Figure 6 is an end view of the same;

Figure '7 is an elevational view of the blank after the shrinking has been performed;

Figure 8 is an end view of the same;

Figure 9- is an elevational view of the blank shown in Figure 7 showing the manner of welding the abutting edges of it together;

Figure 10 is an end view of the welded blank shown in Figure 9;

Figure 11 is an elevational view of the blank at the end of an intermediate step in the formation of the axle housing;

Figure 12 is a cross-sectional view of Figure 11 taken along the line 12-12 looking in the direction of the arrows;

Figure 13 is an elevational view of the completed axle housing formed from the blank shown in Figures 1 to 12, inclusive; and

Figure 14 is a cross-sectional view of the housing taken along the line 14-14 of Figure 13 looking in the direction of the arrows.

Referring now to the drawing in more detail, the axle housings are formed from rolled steel sheet stock of thickness suchas to produce the desired wall thickness of the completed housing at its critical section, i. e., where th banjo frame and throat merge. This is just outside'the ends of the slots 2, 3. In one example, this stock is three-sixteenths of an inch thick. To form the rectangle 1 the stock is cut in any preferred manner, such as by well known shearing machines. The blank thus formed is next punched to form two slots 2 and 3 which are located at the midsection of the blank and with their longer axes parallel to the longer axis of the blank. Preferdesirable to support the edges of the slots 2, 3 while the. sheet is closed into a tube.

This plate is formed into a cylinder, preferably by two punch and die operations, although, if desired, a rolling. operation may be substituted. In Figure 3 I have shown the blank 1 at the completion of the first punch and die operation, which operation forms the blank into a U-shaped member having an arcuate portion 5 whose radius corresponds to the radius of the completed cylinder. It will be noted that the slots 2 and 3 are located at the junction of the arcuate portion 5 and the straight portions 6 and 7 of the blank. The U-shaped member thus formed is of uniform dimension throughout its entire length, that is, the radius of the arcuate portion 5 is the same throughout the entire length of the blank.

To close the blank shown in Figures 3 and 4 into the tube shown in Figures 5 and 6, a cooperating top die, semi-cylindrical in shape, .is brought down over the straight portions 6, 7, folding them toward each other, causing the edges to abut and, by compression, to arch out to fill the die. pressing back into the slots the punchings sheared therefrom, later to be knocked out, or by inserting from the side suitable retractlble plug members in the sides of the die.

At the completion of this step in the process,

the blank 1 is formed into a cylinder 10 which blank. In Figures 5 and 6, the edges are, for

the sake of clearness, shown as separated. They are actually in close contact. With'the slots 2 .and 3 located as shown in Figure 1, this seam 11 is located midway between the slots in the completed cylinder 10. It is contemplated within my invention to have one of the slots together directly with the seam 11 and the other to be opposite the same. I

Although it is preferable to punch the slots 2 and 3 in the plate prior to the operations which form that plate into a cylinder, it is not necessary to do this, as these slots may be subsequently punched or out within the teachings "of my invention. The presence of the slot in the plate, during the operations which form that plate into a cylinder may, in certain instances, be a disadvantage because of the tendency of the slot to collapse during these operations. This tendency must be overcome by properly supporting the edges of the slot during the forming of the cylinder. Ordinarily, such supporting of the edges of the slot affords no great obstacle and it is therefore preferable to punch the slots into place prior to the forming operations.

The cylinder thus formed is next shrunk by passing suitable ring dies longitudinally over the ends to form the end cylinder arm sections 15 and 16 to a smaller diameter than that of the central section 1'7, these end cylinders being connected to the central cylinder 17 by frusto The solts 2, 3 are supported either by I conical sections 18 and 19. The shrinking of ably, although not necessarily so, the slots 2 and 3 are located equidistant from the longitudinal meridian line of theblank 1. The slotting operation may be performedafter the sheet is closed into a tube as disclosed in the application Serial No. 417,581. If the slots are first punched, it is owing to the fact that the compression or arch strength of the cylinder opposes the action of the die. This perfect seating of the abutting edges insures a strong weld in the seam when it is subsequently welded. The swaging or shrinking is performed preferably in several 15 steps, as disclosed in aforesaid application Serial No. 418,827.

After the forming operation has been completed, the seam is welded by any suitable welding process, although preferably a hydrogen weld is made. The weld is as malleable as the stock from which the cylinder is made, so that subsequent forming operations may be performed without injury to the welded seam. This weld 20 is shown in Figures 9 and 10. The last pass throughithe shrinking dies may be made after the weld is formed, if desired.

These operations complete the steps of the process peculiar to my invention. The blank thus formed, and shown in Figures 9 and 10, is subjected-to the forging and finishing operations set forth in the first above mentioned copending application of George Spatta, to form the axle housing shown in Figures 13 and 14.

While a detailed description of the steps in the process employed to form the finished housing are not necessary herein, it is to be noted that the central portion 17 of the blank is heated (see application Serial No. 420,596) and expanded by suitable tools projecting through the slots 2 and 3 to form the wall sections 21 and 22 as parallel flat strips such as are shown in Figures 11 and 12. The operation and the machine for performing the same in detail is disclosed in application Serial No. 425,426. This lateral spreading of the slots 2 and 3 opens them sufficiently to permit the insertion of the banjo forming dies (see application Serial No. 426,545) by which the banjo section 23 is formed. This section is connected to the end cylinders 15 and 16 by throats 24 and 25 which are formed to shape as shown in the application of George Spatta Serial No. 427,204, and the banjo section is provided with an inwardly extending flange 26 which terminates in a circle 27. The flanges are flattened out (see application Serial No. 428.653)

and machined or bored out to provide a gauge surface for the flange forming operation.

After the performance of these operations, the ends of the blank are heated, and the bearing seats 28 and 29 and brake drum flanges 30 and 31 are formed thereon by a series of endwise forging operations (see application Serial No. 430,- 206). Preferably, the races and flanges are formed by a series of operations each of which moves the metal in the blank a short distance, so that the stresses imposed upon the weld in the blank are not excessive. The weld is thereby obliterated in-the forming operation so that the resulting race and flange is truly an integral unit in which the presence of the weld cannot be detected.

Inasmuch as the original thickness of the flange 26 of the banjo 23 is only equal to the thickness of the plate 1, the flange is reinforced with a strip of metal which substantially doubles the flange thickness so that there will be ample stock in which sufilcient threads can be formed to securely seat the stud bolts by which the differential meche cal portion of a length approximately equal to anism of the vehicle is secured in the housing.

From the foregoing it will be apparent to those skilled in the art that my method permits forming a blank from which an axle housing can be made by simple operations performed upon inexpensive stock. Preferably, the forming of the cylinder is performed as described, although it is possible to roll such a cylinder from the flat stock 1, and it is within the contemplation of my invention to do so when desired.

Thecost of the completed axle housing is low because the cost of the hot rolled flat stock from which it is made is low, and the operations performed upon it are simple and relatively inexpensive. The resulting housing is, however, of high quality and entirely satisfactory for the use to which it is to be put.

While I have chosento show and describe my invention in connection with a preferred embodiment of it, I have done so by way of example only, as there are many modiflcations and adaptations which-can be made by one skilled in the art within the teachings of the invention.

Having thus complied with the statutes and shown and described a preferred embodiment of my invention, what I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What is claimed is:--

1. The method of forming a rear axle housing which comprises the following steps, viz.,-shearing a rectangularpiece of stock, punching a pair of oval holes in said piece, forming said piece into a cylinder with the sides of the piece abutting, shrinking the tube by endwise forging to form end cylinders of reduced diameter, then welding the abutted ends of said piece, and forming the blank thus formed into a one piece housing of the required shape.

2. The method of forming a rear axle housing which comprises the following steps, viz., shearing a rectangular piece of stock, punching a pair of oval holes in said piece, pressing said piece into a U-shape with the slots at the junction of the arcuate and straight portions thereof, closing said U to form said piece into a cylinder, shrinking the tube by endwise forging to form end cylinders of reduced diameter, then welding the abutted ends of said piece, and forming the blank thus formed into a one piece housing of the required shape.

3. Method of forming a rear axle housing which comprises, closing a rectangular piece of sheet stock into a tube with the longitudinal edges of the sheet abutting but physically separate from one another, slotting the tube for openings to form a banjo frame, and, while the butting ends of the tube are physically separate from one another, shrinking the ends of the tube by passing ring dies endwise over the arm portions to elongate the arms to increase their wall thickness and to reduce the outer diameter.

4. Method of forming a rear axle housing which comprises, closing a rectangular piece of sheet stock into a tube with the longitudinal edges of the sheet abutting, slotting the tube for openings to form a banjo frame, shrinking the ends of the tube by passing ring dies endwise over the arm portions to elongate the arms to increase their 'wall thickness and to reduce the outer diameter,

and then welding the longitudinal abutting edges to complete the tubular walls.

5. An axle housing blank for making a banjo frame axle housing, comprising a cylinder of hot rolled sheet metal having a central cylindrie the diameter of the banjo frame to be formed,

and end portions of .a smaller diameter and end portions of a smaller diameter and greater wall thickness than that of the central portion,

said blank having a longitudinal split extending.

closing the partially formed cylinder by bringshrinking ing the edges into abutment, passing dies over the end portionsnf the cylinder to reduce the diameter of said end portions, welding the abutting edges, and endwise forging of the ends of the arms to form bearing seats.

'8. The method of making a banjo frame housing from hot rolled sheet stock which comprises punching slots in the flat blank, shaping the ilat blank into a partially closed cylinder, supporting the edges of the slots and simultaneously closing the partially formed cylinder by bringing the edges into abutment, passing shrinking dies over the end portions of the cylinder to reduce the diameter of said end portions, welding the abutting edges, again passing shrinking dies over the end portions of the cylinder to reduce the diameter of said end portions, and endwise forging of theends of the arms to form hearing seats.-

9. The method of forming an axle housing I which comprises, forminga flat sheet 'of hot rolled steel, forming the sheet into a cylinder,

shrinking the ends of the cylinder to form end cylinders integral with and of smaller diameter than the intermediate portion while the two ends of the sheet are adjacent but physically separate from one another, and welding the two adiacent ends of the sheet by a longitudinal weld after the end portions are shrunk.

10. The method of forming an axle housing which comprises, forming a rectangular sheet of hot rolled steel, curving the rectangular sheet to form a cylinder having a slot extending the full length thereof, shrinking the ends to a diameter less than that of the intermediate portion, and then welding the slot by a longitudinally extending weld.

I 11. The method of forming an axle housing which comprises, forming a rectangular sheet of hot rolled steel, curving the rectangular sheet to form a cylinder having a slot extending the full length thereof, shrinking the ends to a diameter less than that of the intermediate portion, then welding the slot by a longitudinally extending weld and, after welding, forming on the end portions an integral bearing seat and a flange.

FRANK HABICHT. 

